DESCRIPTION: Vapor intrusion is the migration of volatile organic chemicals from below ground into overlying buildings and is a major cause of large population exposure to hazardous chemicals. To assess health impacts of exposure to vapor intrusion compounds, monitoring of indoor air is required. Conventional vapor intrusion monitoring is done by on-site sample collection followed by laboratory analysis. Disadvantages of the conventional method include: the need for sample retrieval, extended processing times, inability to adequately track variations in concentration over time and high cost. Portable analysis methods that can be installed or operated and provide continuous and/or short term measurements are needed to solve these problems. This Phase II Small Business Innovation Research proposal addresses this need through a compact cartridge-based sampling and detection method that, when combined with a portable Fourier Transform Infrared (FTIR) spectrometer, can detect vapor intrusion compounds at low concentrations and with high selectivity. The approach incorporates advances in solid phase extraction and exploits novel coatings for optical waveguides. The method is differentiated from most other detection methods because it provides chemical signatures for unambiguous identification of compounds. Additional advantages include: compact/portable size, near real-time results, readily automated, minimal expertise required, reagent- free, solvent-free and embedded telemetry. The Phase I study successfully demonstrated the method's feasibility by detecting chlorinated vapor intrusion compounds at low parts per billion levels. A Phase II follow on study is proposed emphasizing understanding the capabilities of key components used for selective detection and addresses the methods needed for assembly of a function portable device. The study will characterize the devices' performance at a Superfund field site. The impact of this research goes beyond the immediate focus on vapor intrusion monitoring. Improvements in sample preparation methods can be applied wherever portable on-site analysis is desired, such as: workplace safety, forensic analysis, food safety, pharmaceutical manufacture, and drinking water qualities.